The vast number of castles built by powerful rulers occupying every strategic rocky outcrop of the the valleys bear testimony to the extent that these valleys were coveted in the Middle Ages. Bolzano Bozen can boasts about an impressive number of castles. When the town was founded in 1170 AD, it was originally guarded over by a fortress, Weinegg Castle. Its ruins were recently rediscovered on the slopes of the Kohlern mountain, with a frescoed chapel (closed to the public). Nevertheless the most sumptuous and picturesque castle is Runkelstein (Roncolo), dubbed the ‘illustrated castle’, referring to Europe’s most impressive cycle of medieval secular frescoes adorning its rooms and depicting love scenes and the idealized world of chivalry. Maretsch (Mareccio) Castle – renowned for its late renaissance secular frescoes - is singular for being situated in the valley floor surrounded by vineyards, close to the town centre rather than atop an inaccessible crag. Sigmundskron (Firmiano) Castle is situated on a porphyry spur overlooking the confluence of the rivers Etsch (adige) and Eisack (Isarco). It has recently been returned to its former glory, while still remaining a ruin. Built by the Bishop of Trento (who named it ‘Formicaria’) in the 10th century on the site of a former Palaeolithic settlement, it was subsequently bought by the Counts of Tyrol but fell into disrepair in the 16th century. The restoration work adapted the castle in order to accommodate Reinhold Messner’s Mountain Museum. Now it contains a collection old documents narrating South Tyrol’s long strive towards the autonomous status in the 20th century. In 1957 the biggest demonstration in the history of South Tyrol took place there at the instigation of Silvius Magnago. Haselburg (Flavon) Castle stands in a similarly commanding position with view of the Adige Valley as far as Meran, with the imposing Hocheppan Castle dominating the landscape on the opposite side of the valley.